Bodily injuries and ailments are commonly treated by applying a non-ambient temperature material to the affected region of the body. For example, a low temperature material, typically applied in the form of cold water, ice or a cold pack, may advantageously inhibit swelling in the region of the injury. A high temperature material, typically applied in the form of hot water, a hot pack or an active heating element, may advantageously reduce pain and promote healing. A number of splint devices are known in the art for applying non-ambient temperature materials to injured or otherwise ailing regions of the body as evidenced by U.S. Pat. No. 3,548,819 to Davis et al; U.S. Pat. No. 3,901,225 to Sconce; and U.S. Pat. No. 4,706,658 to Cronin. One disadvantage of such devices is that the low temperature materials become warmer as they remain in contact with the body and the body transfers heat to the low temperature materials. Conversely, high temperature materials become cooler as they transfer heat to the body. This disadvantage can be remedied by periodically replacing the non-ambient temperature materials. However, constant replenishment of these materials is cumbersome and inconvenient, and results in periodic treatment temperature fluctuations.
In response to this problem, a number of systems have been developed for continuously circulating a cooling fluid from a low temperature reservoir to a desired body location. Such systems are typified by U.S. Pat. No. 2,726,658 to Chessey; U.S. Pat. No. 3,683,902 to Artemenko et al; and U.S. Pat. No. 4,962,761 to Golden. These fluid circulation systems in general are relatively complex, rendering them costly to manufacture and maintain, as well as difficult to operate. Accordingly, the systems are not practical for widespread use.
U.S. Pat. No. 5,241,951 to Mason et al. incorporated herein by reference discloses a therapeutic treatment system which rectifies the shortcomings of the above-referenced fluid circulation systems. The therapeutic treatment system of U.S. Pat. No. 5,241,951 is relatively simple, rendering it less costly to manufacture and maintain and enabling greater ease of operation than the prior systems. The therapeutic treatment system of U.S. Pat. No. 5,241,951 is operated by circulating a non-ambient temperature heat transfer fluid through a heat transfer pad. Specific examples of heat transfer pads having utility in the therapeutic treatment system of U.S. Pat. No. 5,241,951 are disclosed in commonly-owned U.S. Pat. Nos. 5,417,720; 5,662,695; D.348,106 and D.345,609 all to Mason et al. and all of which are incorporated herein by reference.
The present invention recognizes the need for improved performance of the heat transfer pad in a non-ambient temperature therapy system such as those described above. Accordingly, it is generally an object of the present invention to provide a non-ambient temperature therapy system having a heat transfer pad exhibiting improved performance. This object and others are achieved in accordance with the invention described hereafter.